Correlation Analysis on Single Nucleotide Polymorphism of CAPN1 Gene and Meat Quality and Carcass Traits in Chickens

The selection of meat quality has received considerable focus in chicken breeding. This study was aimed at investigating the effect of CAPN1 gene on meat quality traits in chicken populations. Primer pairs for 3 UTR in CAPN1 were designed from database of chicken genomic sequence. Polymorphisms were detected using PCR-SSCP and DNA sequencing. A mutation at position 9 950 nt （G/A, locus A） was found among individuals in each population. The allele and genotype frequencies significantly differed among eight lines with higher frequencies of allele A2 and genotype AIA2 （P〈0.01）. The least square analysis showed that there was significant difference （P 〈 0.05） in muscle fiber density and some carcass traits among genotypes and that the breast muscle fiber density （BFD） of birds ofAIA1 genotype was significantly higher （P〈0.05） than that of birds ofA2A2 genotype. It was concluded that the CAPN1 gene was the major gene affecting the muscle fiber traits of chicken or was linked with the major gene. These results were useful for studying the molecular mechanism that influences meat traits and were used as the base of molecular-assisted selection to meat quality traits. So, this site may be a potential marker affecting the muscle traits of chickens.     

Sequence Variations in the Bovine IGF-Ⅰ and IGFBP3 Genes and Their Association with Growth and Development Traits in Chinese Beef Cattle

The objective of this study was to determine the genotype effects of the bovine insulin-like growth factor Ⅰ （IGF-Ⅰ） and its binding protein 3 （IGFBP3） genes on growth and development traits in beef cows, including 130 Chinese Simmental, 42 Nanyang, and 47 Luxi Yellow cattle. Sequence variations in the bovine IGF-Ⅰ and IGFBP3 genes were investigated by single strand conformation polymorphism （SSCP）. SSCPs were detected in 6 fragments, which is the 5＇-flanking region, the 2nd exon, the 5th exon, and the 5th intron of the IGF-1 gene, and the 2nd exon, the 3rd exon of the 1GFBP3 gene. Two polymorphisms, an A-to-G transition in the 2rid exon of the IGF-Ⅰ gene and a T-to-C transition in the 2rid exon of IGFBP3 gene were detected in 3 breeds. The allele frequencies of 2 polymorphisms were 0.0411 （A）, 0.9589 （B）, and 0.7237 （A）, 0.2763 （B）, respectively. These 2 loci were analyzed to associate with body weight, height at withers, body length, heart girth, rump width, and beef production index （BPI） at 0, 6, 12, 24, and 36-month old. The IGFBP3 locus was shown to be associated with rump width, heart girth at 24-month and 36-month. Animals with BB genotype had higher rump width （24.86 ± 0.47） cm at 24-month and （27.50 ± 0.63） em at 36-month. The heart girth was highest for the individuals with BB genotype （171.33 ± 1.84） cm and higher than those with AB genotype （166.68 ± 1.13） cm （P〈 0.05） at 36-month.     

Genetic Polymorphism of Kappa Casein （K-CN）in Iraqi Buffalo Using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism

This study was carried out the animal production department, genetic engineering lab, college of agriculture, （UoB）, Iraq. The aim of this study was to use the polymerase chain reaction restriction fragment length polymorphism （PCR-RFLP） as a fast, efficient and low cost method to detect the genetic variants of kappa-casein gene （k-CN） in Iraqi buffalo using three different primers specific for bovine k-CN to amplify the gene segment, followed by digestion using restriction enzyme （Hind III） for genotyping. DNA from 50 Iraqi buffaloes was extracted by phenol chloroform method. PCR was carried out in a final reaction volume of 25 μL and the reaction mixture was subjected to standard PCR protocol. The results of this work show that among the examined 50 Iraqi Buffalo were homozygous for the K-CN and genotyped as BB for all three primers but gave different bands. Thus PCR-RFLP using Hind III revealed all the samples to be monomorphic for this locus. The restriction digestion analysis of 397 bp PCR product of k-CN indicates the presence of two fragments of 154 bp and 225 bp for BB-genotype. A 437 bp fragment of the bovine genomic K-CN gene was amplified. One Hind III restriction site is found in position 346 of the amplified fragment of allele k-CN B, yielded 91 bp and 346 bp. Amplified products from Iraqi buffalo （530）, after being digested with Hind III, yielded two separate DNA fragments of different sizes i.e., 160 bp and 370 bp. For the first time completed research such specifications in Iraq, for the first time using molecular biology in genetic identification. Our objectives of this study have been to aid in understanding domestication, Buffalo origin and their history and evolution, to identify genetically unique breeds, to provide an objective basis for conservation decisions and to aid the formulation of breeding plans.     

Associations of Gonadotropin-Releasing Hormone Receptor （GnRHR） and Neuropeptide Y （NPY） Genes＇ Polymorphisms with Egg-Laying Traits in Wenchang Chicken

Single nucleotide polymorphisms （SNP） of chicken gonadotropin-releasing hormone receptor （GnRHR） and neuropeptide Y （NPY） were selected to identify the genotypes of Wenchang （Chinese indigenous breed） chicken with restricton fragment length polymorphisms. The associations of the SNPs with the total egg production （NE）, average days of continual laying （ADCL）, and number of double-yolked eggs （DYE） traits were analyzed. The frequency of restriction enzyme A/a alleles in the population was for GnRHR 0.69 （Bpu1102 Ⅰ A） and 0.31 （Bpu1102 Ⅰ a） and for NPY 0.46 （Dra Ⅰ B） and 0.54 （Dra Ⅰ b）. Trait data from a total of 120 hens, which were purebred introduced from Hainan Province, China from one generation were recorded. Two significant effects of genes＇ marker were found： for GnRHR and number of eggs （dominant; t= 2.67, df= 116） and NPY and number of eggs （additive; t= 1.97, df= 116）. The current research supports the effects of GnRHR and NPY genes on egg-laying traits of chickens.     

The Effect of Dietary Supplementation with Phytase Transgenic Corn on Growth Performance,Phosphorus Utilization and Excretion in Growing Pigs （Sus scrofa）

Two experiments were conducted to investigate the effect of dietary supplementation with phytase transgenic corn (PTC)on growth performance, phosphorus (P) utilization and excretion in growing pigs. In Exp. 1, 180 pigs (Large White ×Landrace, BW=37.7 kg) were randomly allotted to 4 treatments with 5 replicates of 9 pigs each in order to evaluate the effect of PTC supplementation in low-P diets on growth performance. Four corn soybean meal-based diets consisted of a positive control (PC) diet, a diet containing 500 units (U) of exogenous phytase kg-1 (EP) on the basis of low-P (inorganic P reduced by 0.05% from PC diet) and the low-P+500 (PTC1) or 750 (PTC2) phytase U ofPTC kg-1. In Exp. 2, 20 barrows (Large White×Landrace, BW=31 kg, 4 treatments with 5 replicates of 1 pig each) were randomly selected to evaluate the effect of PTC in low-P diets on serum parameters and nutrient utilization. Diets in Exp. 2 were similar to those in Exp. 1except that the EP group was replaced by a low-P diet without exogenous phytase supplementation as a negative control (NC) group. The results from Exp. 1 showed that the average daily gain (ADG) in the PTC2 group was significantly higher (P＜0.05) than that in the EP group over all periods. On the other hand, the feed:gain (F:G) ratio of the EP group was significantly higher (P＜0.05) than that of the PTC2 group during 1-21 and 1-42 d, respectively. There were no differences in average daily feed intake (ADFI) among all treatments (P＞0.05). The results from Exp. 2 showed that the concentration of serum Ca in the NC group was the highest (P＜0.05), while the concentration of serum P in the PTC2 group was the highest (P＜0.05) among all treatments. There was a significant decrease (P＜0.05) in the P apparent digestibility of the NC group compared with the other groups, and that of PTC2 group was the best. Furthermore, fecal P excretion was reduced (P＜0.05) from 1.80 g d-1 in the PC group to 1.28 g d-1 in the PTC2 group. In conclusion, dietary supplementation with PTC could reduce the application of inorganic P, decrease fecal P excretion, and improve the growth performance of growing pigs.     

Genetic Diversity Analysis of Cultured Populations of Jade Perch （Scortum bacoo） in China Using AFLP Markers

Genetic diversity of three cultured populations of jade perch （Scortum bacoo） are studied using amplified fragment length polymorphism （AFLP） markers, which is Guangzhou（GZ） population, Foshan （FS） population and Qingdao（QD） population. Nine primer combinations were used and 385 fragments were detected. Among the 385 fragments, 80 bands （20.78%） were polymorphic. And it can be speculated that the genetic diversity of the three cultured populations of jade perch was very poor according to the gene genetic diversity among populations （Ht）, the gene genetic diversity within populations （Hs） and Shannon-Weiner index （I）. From gene differentiation （Gst）, genetic distance （D）, genetic similarity （5）, and UPGMA analysis, it is found that the relationship among the three populations is very closed, and the difference in genetic diversity among the three populations is not significant. Further clustering relationships of the jade perch cultured populations also are correlated to historical-breeding observations and genetic relationships. The GZ population clustered together with the QD population first, then with FS population.